Xiao Yunhua, Liu Xueduan, Dong Weiling, Liang Yili, Niu Jiaojiao, Gu Yabing, Ma Liyuan, Hao Xiaodong, Zhang Xian, Xu Zhen, Yin Huaqun
School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China.
Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
Arch Microbiol. 2017 Jul;199(5):757-766. doi: 10.1007/s00203-017-1342-9. Epub 2017 Mar 4.
This study used an artificial microbial community with four known moderately thermophilic acidophiles (three bacteria including Acidithiobacillus caldus S1, Sulfobacillus thermosulfidooxidans ST and Leptospirillum ferriphilum YSK, and one archaea, Ferroplasma thermophilum L1) to explore the variation of microbial community structure, composition, dynamics and function (e.g., copper extraction efficiency) in chalcopyrite bioleaching (C) systems with additions of pyrite (CP) or sphalerite (CS). The community compositions and dynamics in the solution and on the ore surface were investigated by real-time quantitative PCR (qPCR). The results showed that the addition of pyrite or sphalerite changed the microbial community composition and dynamics dramatically during the chalcopyrite bioleaching process. For example, A. caldus (above 60%) was the dominant species at the initial stage in three groups, and at the middle stage, still dominated C group (above 70%), but it was replaced by L. ferriphilum (above 60%) in CP and CS groups; at the final stage, L. ferriphilum dominated C group, while F. thermophilum dominated CP group on the ore surface. Furthermore, the additions of pyrite or sphalerite both made the increase of redox potential (ORP) and the concentrations of Fe and H, which would affect the microbial community compositions and copper extraction efficiency. Additionally, pyrite could enhance copper extraction efficiency (e.g., improving around 13.2% on day 6) during chalcopyrite bioleaching; on the contrary, sphalerite restrained it.
本研究使用了一个包含四种已知中度嗜热嗜酸菌的人工微生物群落（三种细菌，包括嗜热栖热硫化杆菌S1、嗜热硫化氧化硫杆菌ST和嗜铁钩端螺旋菌YSK，以及一种古菌，嗜热铁原体L1），以探究在添加黄铁矿（CP）或闪锌矿（CS）的黄铜矿生物浸出（C）系统中微生物群落结构、组成、动态和功能（如铜提取效率）的变化。通过实时定量PCR（qPCR）研究了溶液和矿石表面的群落组成和动态。结果表明，在黄铜矿生物浸出过程中，添加黄铁矿或闪锌矿显著改变了微生物群落组成和动态。例如，在三组实验的初始阶段，嗜热栖热硫化杆菌（超过60%）是优势菌种，在中期，C组（超过70%）仍以其为主导，但在CP组和CS组中被嗜铁钩端螺旋菌（超过60%）取代；在最终阶段，嗜铁钩端螺旋菌在C组占主导，而在矿石表面嗜热铁原体在CP组占主导。此外，添加黄铁矿或闪锌矿均使氧化还原电位（ORP）以及铁和氢离子浓度升高，这会影响微生物群落组成和铜提取效率。此外，黄铁矿可提高黄铜矿生物浸出过程中的铜提取效率（如在第6天提高约13.2%）；相反，闪锌矿则起到抑制作用。
